A urbanização crítica na metrópole de São Paulo, a partir de fundamentos da geografia urbana

Over time the city has been involved in constant changes related with its diversity, processes and internal structure. As urban reality, the concepts of urban geography as a discipline shows a metamorphosis based on the agitation of urban reality. This investigation aims to update the geographical literature, without extreme simplifications and including as much perspectives as possible. Pierre George gives and extraordinary example about the extension of that knowledge, abruptly become obsolete.

Brazilian territorial dynamics and the inversion of the ""frontier thesis"" in the southern new world

It is a generally acknowledged fact that the dynamics of frontier advance deeply influenced the broad experience of American post colonial societies. The colonization, which started most from the east boundaries of the continent, appropriated and gradually transformed the American territories from east to west. The advance, initially represented by the arrival of the European settlers, went on to become an important trace of that society which did not come to know any physical limits of a restricted territory. However, despite the common identity granted by these territorial dynamics, the later developments and consequences seem to have shaped differently the Northern representatives from their Southern counterparts. In addition, the interpretation of these facts bore in each of these regions different meanings and traits.

Sociedade e gestão do risco: o aquífero Guarani em Ribeirão Preto-SP, Brasil

Contemporary society creates risks of all kinds, changing the meaning of this term. Although it may be associated with natural hazards, it gradually assumes a stronger relation with human actions, especially due to the use of technology. The use of land for agricultural and urban activities creates the possibility of contamination in the recharge area of the Guarani aquifer in the municipality of Ribeirao Preto, state of Sao Paulo, Brazil. This city is one of the most important in the state with high economic development. Besides this, it is located in the recharge area of the main reservoir of underground water of South Cone. This paper aims to discuss the management of groundwater use in Ribeirao Preto and reflects the risk that contamination and overexploitation might cause to the main city's water supply.

Sedimentary Organic Matter in Cores of the Cananeia-Iguape Lagoonal-Estuarine System, Sao Paulo State, Brazil

Sedimentary organic matter is a good tool for environmental evaluation where the sediments are deposited. We determined the elemental and C- and N-isotopic compositions of 211 sub-surface sediment samples from 13 cores (ranging from 18 to 46cm), collected in the Cananeia-Iguape estuarine-lagoonal system. The aim of this research is to evaluate the environmental variations of this tropical coastal micro-tidal system over the last decades, through SOM distribution. The studied parameters show differences between the cores located in the northern (sandy-silt sediments) and southern (sand and silty-sand) portions. The whole area presents a mixed organic matter origin signature (local mangrove plants: < -25.6 parts per thousand PDB/ phytoplancton delta(13)C values: -19.4 parts per thousand PDB). The northern cores, which submitted higher sedimentation deposition (1.46cm year(-1)), are more homogenous, presenting lower delta(13)C (< -25.2 parts per thousand PDB) and higher C/N values (in general >14), directly related to the terrestrial input from Ribeira de Iguape River (24,000 km(2) basin). The southern portion presents lower sedimentation rates (0.38cm year(-1)) and is associated to a small river basin (1,340 km(2)), presenting values Of delta(13)C: -25.0 to 23.0 parts per thousand PDB and of C/N ratio: 11 to 15. In general, the elemental contents in the 15 cores may be considered from low to medium (< 2.0% C - < 0.1% N), compared to similar environments. Although a greater marine influence is observed in the southern system portion, the majority of the cores present an elevated increase of continental deposition, most likely related to the strong silting process that the area has been subjected to since the 1850s, when an artificial channel was built linking, directly, the Ribeira River to the estuarine-lagoonal system.

Late Pleistocene and Holocene vegetation changes in northeastern Brazil determined from carbon isotopes and charcoal records in soils

Northeastern Brazil represents a strategic area in terms of Quaternary records of environmental changes in South America due to its distinct semi-arid climate in near equatorial latitudes. In this study, carbon isotope and charcoal distribution records in soils are used to characterize vegetation dynamics, forest fires and their relation to climate change since the Late Pleistocene in the States of Ceara, Piaui and Paraiba, Northeastern Brazil. At the Ceara site, the carbon isotope record showed an enrichment trend from -24%(o) to 19%(o) during the early-mid Holocene, indicating an opening of vegetation and expansion of savanna vegetation (C(4) plants) during this period. A trend toward more depleted delta(13)C values (similar to-32%.) in the late Holocene indicates an expansion of forest vegetation (C(3) plants). A similar trend is observed at the Piaui and Paraiba sites where values of similar to-24%0 are associated with open forest vegetation during the late Pleistocene. In the early-mid Holocene, delta(13)C values of up to -18.0%(o), suggest the expansion of C4 plants. Based on the carbon isotope data, it is postulated that from similar to 18,000 cal yr B.P. to similar to 11,800 cal yr B.P.-similar to 10,000 cal yr B.P. arboreal vegetation was dominant in northeastern Brazil and is associated with humid climates. The savanna expanded from similar to 10,000 cal yr B.P. to similar to 4500-3200 cal yr B.P. due to a less humid/drier climatic phase, also supported by the significant presence of fires (charcoal fragments in the soil). From approximately 3200-2000 cal yr B.P. to the present, carbon isotope records suggest forest expansion and a more humid phase. These results form part of a regional pattern since they are in agreement with paleovegetation records obtained in regions of Maranhao, northeastern Brazil and in the Amazon and Rondonia States, northern Brazil. (C) 2010 Elsevier B.V. All rights reserved.

Quaternary paleoenvironments and relative sea-level changes in Marajo Island (Northern Brazil): Facies, delta(13)C, delta(15)N and C/N

The reconstruction of physical environments of Amazonian areas is of great interest to determine the dynamic evolution of the Amazon drainage basin. However. few studies have emphasized the Quaternary deposits in this region. which is mostly due to the lack of natural exposures imposed by the low topography. This work integrates facies analysis. radiocarbon dating, delta(13)C, delta(15)N, and C/N of an 124 m-thick core from an area located at the mouth of the Amazon River. northeastern Amazonia. The study records deposits up to 50.795 (14)C yr B P. in age. which formed in a variety of depositional environments including fluvial channel, tidal flat, outer estuarine basin to shallow marine. inner estuarine basin, estuarine channel and lagoon. Facies interpretation was significantly improved with the inclusion of delta(13)C, delta(15)N, and C/N analyses of organic matter extracted from the sediments The obtained values conform to a transitional. mostly estuarine paleosetting evolved during successive relative sea-level fluctuations. The results suggest fluvial deposition between 40,950 (+/- 590) and 50.795 (14)C yr B P, with a rise in relative sea level that commenced between 35,567 (+/- 649) and 39,079 (+/- 1114) (14)C yr B P. An overall transgression took place until 29,340 (+/- 340) (14)C yr B P., after which the relative sea level dropped, favoring valley rejuvenation and incision. Following this time up to 10,479 (+/- 34) (14)C yr B.P. a rise in relative sea level filled up the valley with estuarine deposits After 10.479(+/- 34) (14)C yr B.P., the estuary was replaced by a lagoon At the end of the Holocene, the coastline prograided approximately 45 km northward, replaci ng the lagoon by a lake system Despite the influence of eustatic fluctuations. regional tectonics played a significant role to create new space where these Late Pleistocene and Holocene sediments accumulated. (C) 2009 Elsevier B V All rights reserved.

Last glacial maximum (LGM) vegetation changes in the Atlantic Forest, southeastern Brazil

This study was carried out in a continental Atlantic Forest located in the southern region of Sao Paulo State, southeastern Brazil. The aim of the study was to evaluate the vegetation dynamics in similar to 70 km forest ecosystem transect that occurred during the late Pleistocene and Holocene in this region, using the stable carbon isotopes (delta C-13) analysis on soil organic matter (SOM) and the C-14 dating of buried charcoal fragments and the humin fraction of SOM. The isotope data (delta C-13) of SOM in the deeper horizons, indicating the presence of more open vegetation than the present, with a probable mixture of C-3 and C-4 plants, suggesting the presence of a drier climate in the period of similar to 20 ka to similar to 16-14 ka BP. From similar to 16 to 14 ka BP to the present, a significant predominance Of C3 plants was observed, indicating an expansion of the forest, probably associated with the presence of a more humid climate than the previous period. The results indicated the presence of open vegetation during the late glacial, probably associated with a drier period, also observed in other regions of Brazil. The Atlantic Forest ecosystem seems to have developed at least since the early Holocene in Southeastern Brazil. (c) 2007 Elsevier Ltd and INQUA. All rights reserved.

Phylogeography of the cactophilic species Drosophila gouveai: demographic events and divergence timing in dry vegetation enclaves in eastern Brazil

Aim The aim of this study was to assess the causal mechanisms underlying populational subdivision in Drosophila gouveai, a cactophilic species associated with xeric vegetation enclaves in eastern Brazil. A secondary aim was to investigate the genetic effects of Pleistocene climatic fluctuations on these environments. Location Dry vegetation enclaves within the limits of the Cerrado domain in eastern Brazil. Methods We determined the mitochondrial DNA haplotypes of 55 individuals (representing 12 populations) based on sequence data of a 483-bp fragment from the cytochrome c oxidase subunit II (COII) gene. Phylogenetic and coalescent analyses were used to test for the occurrence of demographic events and to infer the time of divergence amongst genetically independent groups. Results Our analyses revealed the existence of two divergent subclades (G1 and G2) plus an introgressed clade restricted to the southernmost range of D. gouveai. Subclades G1 and G2 displayed genetic footprints of range expansion and segregated geographical distributions in south-eastern and some central highland regions, east and west of the Parana River valley. Molecular dating indicated that the main demographic and diversification events occurred in the late to middle Pleistocene. Main conclusions The phylogeographical and genetic patterns observed for D. gouveai in this study are consistent with changes in the distribution of dry vegetation in eastern Brazil. All of the estimates obtained by molecular dating indicate that range expansion and isolation pre-dated the Last Glacial Maximum, occurring during the late to middle Pleistocene, and were probably triggered by climatic changes during the Pleistocene. The current patchy geographical distribution and population subdivision in D. gouveai is apparently closely linked to these past events.

Drizzle and Fog Analysis in the Sao Paulo Metropolitan Area: Changes 1933-2005 and Correlations with other Climate Factors

In order to improve our understanding of climate change, the aim of this research project was to study the climatology and the time trends of drizzle and fog events in the Sao Paulo Metropolitan Area, and the possible connections of this variability with the sea surface temperature (SST) of the Atlantic and Pacific Oceans. The climatology of both phenomena presents differences and similarities. Fog shows a marked maximum frequency in winter and a minimum frequency in summer, while the seasonal differences of drizzle occurrence are less pronounced, there is a maximum in spring, whereas the other seasons present smaller and similar numbers of events. Both phenomena present a negative trend from 1933 to 2005 which is stronger for fog events. A multivariate statistical analysis indicates that the South Atlantic SST could increase warm temperature advection to the continent. This could be one of the responsible factors for the negative tendency in the number of both fog and drizzle events.

Fast or slow melting of the Marinoan snowball Earth? The cap dolostone record

The end of the Neoproterozoic era is punctuated by two global glacial events marked by the presence of glacial deposits overlaid by cap carbonates. Duration of glacial intervals is now consistently constrained to 3-12 million years but the duration of the post-glacial transition is more controversial due to the uncertainty in cap dolostone sedimentation rates. Indeed, the presence of several stratabound magnetic reversals in Brazilian cap dolostones recently questioned the short sedimentation duration (a few thousand years at most) that was initially suggested for these rocks. Here, we present new detailed magnetostratigraphic data of the Mirassol d`Oeste cap dolostones (Mato Grosso, Brazil) and ""bomb-spike"" calibrated AMS (14)C data of microbial mats from the Lagoa Vermelha (Rio de Janeiro, Brazil). We also compile sedimentary, isotopic and microbiological data from post-Marinoan outcrops and/or recent depositional analogues in order to discuss the deposition rate of Marinoan cap dolostones and to infer an estimation of the deglaciation duration in the snowball Earth aftermath. Taken together, the various data point to a sedimentation duration in the range of a few 10(5) years. (C) 2010 Elsevier B.V. All rights reserved.

Flood Risk Assessment in Coastal Drainage Basins through a Multivariate Analysis within a GIS-Based Model

This paper presents a GIS-based multicriteria flood risk assessment and mapping approach applied to coastal drainage basins where hydrological data are not available. It involves risk to different types of possible processes: coastal inundation (storm surge), river, estuarine and flash flood, either at urban or natural areas, and fords. Based on the causes of these processes, several environmental indicators were taken to build-up the risk assessment. Geoindicators include geological-geomorphologic proprieties of Quaternary sedimentary units, water table, drainage basin morphometry, coastal dynamics, beach morphodynamics and microclimatic characteristics. Bioindicators involve coastal plain and low slope native vegetation categories and two alteration states. Anthropogenic indicators encompass land use categories properties such as: type, occupation density, urban structure type and occupation consolidation degree. The selected indicators were stored within an expert Geoenvironmental Information System developed for the State of Sao Paulo Coastal Zone (SIIGAL), which attributes were mathematically classified through deterministic approaches, in order to estimate natural susceptibilities (Sn), human-induced susceptibilities (Sa), return period of rain events (Ri), potential damages (Dp) and the risk classification (R), according to the equation R=(Sn.Sa.Ri).Dp. Thematic maps were automatically processed within the SIIGAL, in which automata cells (""geoenvironmental management units"") aggregating geological-geomorphologic and land use/native vegetation categories were the units of classification. The method has been applied to the Northern Littoral of the State of Sao Paulo (Brazil) in 32 small drainage basins, demonstrating to be very useful for coastal zone public politics, civil defense programs and flood management.

Landscape perception by forest understory birds in the Atlantic Rainforest: black-and-white versus shades of grey

Even among forest specialists, species-specific responses to anthropogenic forest fragmentation may vary considerably. Some appear to be confined to forest interiors, and perceive a fragmented landscape as a mosaic of suitable fragments and hostile matrix. Others, however, are able to make use of matrix habitats and perceive the landscape in shades of grey rather than black-and-white. We analysed data of 42 Chiroxiphia caudata (Blue Manakin), 10 Pyriglena leucoptera (White-shouldered Fire-eye) and 19 Sclerurus scansor (Rufous-breasted Leaftosser) radio-tracked in the Atlantic Rainforest of Brazil between 2003 and 2005. We illustrate how habitat preferences may determine how species respond to or perceive the landscape structure. We compared available with used habitat to develop a species-specific preference index for each of six habitat classes. All three species preferred old forest, but relative use of other classes differed significantly. S. scansor perceived great contrast between old forest and matrix, whereas the other two species perceived greater habitat continuity. For conservation planning, our study offers three important messages: (1) some forest specialist species are able to persist in highly fragmented landscapes; (2) some forest species may be able to make use of different anthropogenic habitat types to various degrees; whereas (3) others are restricted to the remaining forest fragments. Our study suggests species most confined to forest interiors to be considered as potential umbrella species for landscape-scale conservation planning.

Is bird incidence in Atlantic forest fragments influenced by landscape patterns at multiple scales?

The degree to which habitat fragmentation affects bird incidence is species specific and may depend on varying spatial scales. Selecting the correct scale of measurement is essential to appropriately assess the effects of habitat fragmentation on bird occurrence. Our objective was to determine which spatial scale of landscape measurement best describes the incidence of three bird species (Pyriglena leucoptera, Xiphorhynchus fuscus and Chiroxiphia caudata) in the fragmented Brazilian Atlantic forest and test if multi-scalar models perform better than single-scalar ones. Bird incidence was assessed in 80 forest fragments. The surrounding landscape structure was described with four indices measured at four spatial scales (400-, 600-, 800- and 1,000-m buffers around the sample points). The explanatory power of each scale in predicting bird incidence was assessed using logistic regression, bootstrapped with 1,000 repetitions. The best results varied between species (1,000-m radius for P. leucoptera; 800-m for X. fuscus and 600-m for C. caudata), probably due to their distinct feeding habits and foraging strategies. Multi-scale models always resulted in better predictions than single-scale models, suggesting that different aspects of the landscape structure are related to different ecological processes influencing bird incidence. In particular, our results suggest that local extinction and (re)colonisation processes might simultaneously act at different scales. Thus, single-scale models may not be good enough to properly describe complex pattern-process relationships. Selecting variables at multiple ecologically relevant scales is a reasonable procedure to optimise the accuracy of species incidence models.

Phylogenetic relationships, diversification and biogeography in Neotropical Brotogeris parakeets

Aim We present a molecular phylogenetic analysis of Brotogeris (Psittacidae) using several distinct and complementary approaches: we test the monophyly of the genus, delineate the basal taxa within it, uncover their phylogenetic relationships, and finally, based on these results, we perform temporal and spatial comparative analyses to help elucidate the historical biogeography of the Neotropical region. Location Neotropical lowlands, including dry and humid forests. Methods Phylogenetic relationships within Brotogeris were investigated using the complete sequences of the mitochondrial genes cyt b and ND2, and partial sequences of the nuclear intron 7 of the gene for Beta Fibrinogen for all eight species and 12 of the 17 taxa recognized within the genus (total of 63 individuals). In order to delinetae the basal taxa within the genus we used both molecular and plumage variation, the latter being based on the examination of 597 skin specimens. Dates of divergence and confidence intervals were estimated using penalized likelihood. Spatial and temporal comparative analyses were performed including several closely related parrot genera. Results Brotogeris was found to be a monophyletic genus, sister to Myiopsitta. The phylogenetic analyses recovered eight well-supported clades representing the recognized biological species. Although some described subspecies are diagnosably distinct based on morphology, there was generally little intraspecific mtDNA variation. The Amazonian species had different phylogenetic affinities and did not group in a monophyletic clade. Brotogeris diversification took place during the last 6 Myr, the same time-frame as previously found for Pionus and Pyrilia. Main conclusions The biogeographical history of Brotogeris implies a dynamic history for South American biomes since the Pliocene. It corroborates the idea that the geological evolution of Amazonia has been important in shaping its biodiversity, argues against the idea that the region has been environmentally stable during the Quaternary, and suggests dynamic interactions between wet and dry forest habitats in South America, with representatives of the Amazonian biota having several independent close relationships with taxa endemic to other biomes.

Areas of endemism in the Antarctic - a case study of the benthic hydrozoan genus Oswaldella (Cnidaria, Kirchenpaueriidae)

Aim The aim of this study is to investigate areas of endemism within the distribution of Oswaldella species in the Southern Ocean, thereby testing previous hypotheses and proposing alternative scenarios for Antarctic evolution. Location Southern Ocean, Antarctic and sub-Antarctic waters of southern South America. Methods We prepared a database for the 31 currently known species of the Antarctic genus Oswaldella, which includes geographical locations gathered from published taxonomic studies as well as materials from museums and expeditions. A parsimony analysis of endemicity (PAE) was used to test hypotheses of distribution patterns. Results Four areas of endemism are hypothesized: southern South America, two high Antarctic areas (eastern and western) and a larger area, mainly in western Antarctica at lower latitudes and including insular areas (but not the Balleny Islands). Main conclusions The results support, in part, previous hypotheses for the Southern Ocean region, while providing more detailed resolution. The areas of endemism may reflect both historical and ecological processes that influenced the Antarctic biota. The Magellanic area reflects the well-known affinities of the Antarctic biota with that of South America and may be a consequence of dispersal through deeper (and colder) waters, followed by speciation. The second area, the largest one, encompasses most of the insular faunas and may also be associated with deeper waters formed since 43 Ma. The third area may be explained by the development of seaways in the circum-Antarctic region beginning 50 Ma. Finally, the fourth zone, with a very poor fauna, coincides with the opening of the Tasman Strait and the formation of the Australo-Antarctic Gulf, associated with a minor wind-driven current.